Folding square



A 1,554,519 J. w. PEARL FOLDING SQUARE sept. 2z, i925.

Filed July 21, 1924 *#"W ATTORNEKl Patented Sept. 22, 1925.

UNITED STATES;

JOSEPH W. PEARL,

PATENT omer..

Kersen, Wasnmeron, fzissienon or @Nn-Hans 'ro JOHN. Burton, or Kurse, WASHINGTON. "I i i roLniNe savana'.

Application led July 2l,

To all whom t may concern.'

Be it known that I, Josnrn W.A PEARL, a citizen or the United States,f residing at Kelso, in the county of Covvlitz and yState ot' Washington, have invented certain new and useful Improvements in Folding Squares, of which the following isa speciiifv cation. H

This invention relates to improvements in squares of the 'foldingr type, and particu-` larly to squares that are adjustable to various angular positions.

The object oi my invention is the provision of a square of improved and simplilied construction over that type of square shown and described in my prior United States patent numbered 1,161,961, issued November so, 1915.

A further object ot my invention isto provide a square simple Yand convenient in use use wherein a relatively movable blademeniber may bey quickly and readily closed or opened and set at various predetermined angles without manipulation ot the retaining devices.

n still 'further object ot my invention is the provision `ot novel and automatically o )uniting rstaining-devices set flush with or belouv the plane sides of the blade-members to `releasably secure them at various adjusted positions, consisting` in spring-catch yieldingly mounted upon one or said members and (zo-operating with suitably spaced notches in the other member whereby the parts may be accurately and securely positioned in their adjusted, angular relations.

Other ob'ects and advanta'es and ob'ects f relating to' details oit construct-ion and arrangement oi. parts will be readily apparent in the detailed description to follow.

In the accompanying drawings, the views illustrate by Way oit example an embodiment or' lmy invention, in which:

Figure lis a plan view of a square embodying my. invention shown in vfolded conj dition.

Fig. 2 is a similar vieu7 of the invention shown in fully open condition.

Fig. 3 is an enlarged view in cross-section on line 3-3 or Fig. 2.

Fig. 4 is a fragmentary plan View or one or the blade-elements of the invention, detached.

Fig. 5 is a view similar to Fig. 4 of the 1924. sensu No. 727,227.,

complementary blade-element of the invention. y

Referring' to said views, the reference numeral 1 indicates one of theblade-members of 4my improved square and 2 'the `comple-` mental-y blade-member which are l hingedly secured together bya pivot-pin flush With the plane sides of the squar`e`- at each of its*- ends. -Said blades may be made of metal, Celluloid or other suitable material and are of flat rectangular configura"tion.,` The blade 1` is ytor-ined at one end With projection 4 extending beyond the inner Y straight edge 5 of the blade and is formed' with a circlari beveled margin 6 concentric With said pivot 3 and with a straight margin -7 at right` angles to said edge 45; A circular-recess 8 also concentric with said pivotis formedon;

one-half of the thickness of the blade and 1 includes the projection 4 Whichis thus onehali' of the thick-ness of the Ina-jor portion ot the blade.` Ashoulder 10i'is formed at -the base of said projection 4 at approximately one-hal'f the distance between the outer yedge 11 of the blade 1 anda line extended from the said inner edge 5.

The other blade 2 is formed with a projection 121ot'1circula`r configuration upon its outer margin 13 which is beveled' to vintertit Within the recess 8 and dovetail 9 ef they other member and having said pivot 3 ras its center. 15 disposed at right angles to its inner straight edgel and formed vvitha shoulder 17 adapted toienga-ge the shoulder 10A when the `blades are their furthest extended j' or] right-angled positions.` Said` blade --2 is cirlcularly recessed at 18 abouty said pi-votfto aboutone-half the thickness of the blade and including the prjection 12,the"

circular margin 2() of said recess '18 isfunderc'ut to Va dovetail groove to slidably edge (ifo-f projecreceive the beveled tion 4.'

Said recess Blade 2 has al straightportion This when assemblea ne" matter distance between the edge 15 of the projection 12 and the outermost edge of said projection so that when folded the outer end 21 of the projection 4 will still be retained in the dovetailed margin 20 of the recess 18 giving strength and solidity to the instrument when in folded condition.

A longitudinally extending slot 22 is formed in said blade 1 having its outer end opening into the recess 8, said slot being about the depth of said recess. A springdog23 is rigidly secured at one end 25 in said slot and is formed at its opposite end in an angular head 26 yieldingly extending into the recess 8. Said projection 12 of the blade 2 is formed with a plurality of angular notches 27 corresponding in shape with the head 26 of the spring-dog and respectively positioned about the circularedge 13.

of the projection in position with respect to the head26 corresponding yto the desired angles at whichthe blade 2 is to be set relative to the blade 1. Also a notch 28 is positioned ata point in 'the periphery of said projection 12 corresponding to the, position that the head 26 will-occupy relative tofsaid' projection when the blades are folded so thatthe blades vwill be reliably l held together when they are linoperzitive as a square.

It will fbe seen' thatthe invention provides a very convenient and serviceable instrumentvfor all' classes of mechanics employing squares of this character Where various angular measurements are to be taken. No

.projections extend from the plane faces or the blades and no other manipulations are M'required to change the angles between the blades than simply separating or closing the blades more or less with the hands as the head26 of the dog'willreadily release `from the respective notchesand enter the desired notch by a mild pressureexerted on the ends of the blade's-by the operator.

lVhileI have described my invention with considerable detail it will be seen to be very simple in construction and practicable in vuse'. vI' wish it to be understood that I margin being received in a groove in the respective recess, a shoulder formed upon one of said blades midway between its lateral edges, and a shoulder formed upon the other said blade adapted to engage lsaid first named shoulder when fully opened and extending midway between the said straight edge of its projection and the curved extremity of said projection.

2. A folding square formed of two blades pivoted together, each said blade having a recess formed in its side and a rojection having a beveled edge iii'terittmg in a groove in said recesses, respectively, veach said projection having a straight edge at right angles to the lateral edges of the blade, J5

shoulder upon the other of said blades extending beyond the projection in the firstnamedfblade when the blades are in folded condition. .c

3. A folding square formed of two blades pivoted together, each blade having a recess formed in. its side and a projection engaged in the recess of the complementary blade, each said projection having a circular margin and an oppositely disposed straight edge at right angles to the respective blade, one of said projections having spaced notches formed in its periphery, a spring-dog mount-- ed in the other of said blades adapted to engage said notches, respectively, a shoulder formed on one of said blades midway between its lateral edges, and a shoulder formed on the other of said blades adapted to engage said first named shoulder when the square is fully opened and extending midway between the Vsaid straight edge of the projection of said blade and the curved extremity of said projection.

4:. A folding square formed of two blades pivoted together, each said blade having a grooved recess formed in its side and a projection having a beveled edge inter-fitting in the grooved recess of the other blade, each said projection having a straight edge at right angles to the lateral edges of the blade, a shoulder formed upon one of said blades midway between its lateral edges, a shoulder upon the other of saidy blades arranged to engage the first named shoulder asa stop when the blades are in ilight-angular position, one of said projections having spaced notches formed in its periphery, and a spring-dog mounted on the other of said blades adapted to engage in said notches,

respectively. JOSEPH W PEARL 

